The future beckons for bearing packages

It seems packages with bearings in them and built-to-order solutions are seen as the big growth product areas, rather than traditional bearings supplied from a catalogue. At the same time, advances are being made in materials, thinness, smallness and improved bearing selection software, all of which have an effect on the manufacturing costs of final products and their performance and reliability. Typical of the view of many makers and vendors of bearings is the opinion expressed by Brian Steel, managing director of DLMP, whose company makes linear products. He sees the future of his business as providing special packages. “We make all the mechanical parts now, everything except the motor on the end. We are now mainly a service industry: since most of our customers now use just-in-time, there is no opportunity for long production runs. Advances in information technology, however, help us customise.” Unlike those who are exporting their manufacturing to the Far East, he believes that “making our own products allows us to control prices.” This is in a market, where he finds that new customers tend to open the conversation along the lines of “are you the people who can save us money?” Malcom Sheryn of Wyko says his company is also finding it profitable to supply specials to order. In Wyko’s case, these include bearings for Formula One racing cars and cryogenics equip[ment, deliverable within seven days. Neither market is, he adds, best served by standard bearings from a catalogue. Formula One demands high speeds and loads with very high reliability for relatively short service lives. Cryogenics, on the other hand, demands special steels that do not become brittle at low temperatures. T. Dent McCartney, general manager of the Dodge division of Rockwell Automation, also envisages a trend towards pre-packaged bearing assemblies, particularly with regard to rotary bearings for use in arduous environments. He says that pre-packaged assemblies are becoming common in the US market while still relatively unusual in Europe. With pre-sealed and pre-lubricated inserts, it is, he explains, possible to reduce assembly times from one hour to less than 15 minutes. Best of all, “you can make things so simple that nobody can screw it up.” As well as reducing assembly costs, the use of pre-packaged assemblies eliminates the introduction of contaminants. This is, apparently, particularly important for the after-market in the quarrying and mining industries. Being a US company, the company’s products were previously only available in Imperial sizes, but are now being made available in metric equivalents. Customers of IKO Nippon Thompson are also increasingly asking for complete solutions, according to UK sales manager Dan Ford, with bearings and motors mounted in a single package. The company’s most striking new product is a miniature linear slide with a rail just 2mm wide which is intended for the manipulation of fibre optics and applications within the electronics industry. Prices are quoted as “sub-£100”, depending on length. Linear products can be made maintenance-free by incorporating a plastic band impregnated with lubricant. In rotating bearings, the same effect can be achieved by incorporating a cage made of similar material. Lubricant is released as the bearing approaches its working temperature. The smallest bearings on display at the recent Drives and Controls exhibiton were some of those on the stand of PBI International, which is based in Canterbury. Managing director Yago Zens showed Eureka 3mm OD ball bearings, each equipped with six 1/3mm diameter balls. The shaft diameter was 1mm. “Everything is getting small”, he elaborated, adding that that these bearings, Japanese-made and costing from £1 to £1.50 each in sufficient quantity, are finding applications in electric model trains, hard disk drives and microwaves. Recent applications include mechanical watches, but not yet the best quality Swiss ones, and as a replacement for bushings in trumpets. R.A.Rodriguez’s latest Kaydon Ultra Slim bearings have a cross section of only 2.5mm yet possess a full complement of balls and are supplied in bore sizes from 35mm to 170mm. Bearings products manager David Hey claims the future lies with thin sections, explaining how such products had originally been developed for the semiconductor industry as a replacement for plain bearings in order to eliminate the production of particulates. To combat corrosion resistance they can be made of stainless steel and may be specified for angular, radial or four point contact. Another option is a hybrid version with ceramic balls. The ceramic balls carry the load and are spaced apart by stainless steel balls. Applications include robotics, inspection equipment, satellites and cameras. Not all bearings have rolling elements, of course. Matthew Aldridge of igus reckons the first requirement of his customers is reduced maintenance and a desire to fit and forget. Solid state polymer bearings are often ideal, provided they have the load bearing and speed capabilities required for the application. For this reason, igus has now produced version 2.11 of its ‘medias’ professional software to make accurate life predictions for its range of products. The software is available free of charge on CD or can be downloaded on-line from www.igus-uk.co.uk. Aldridge says the predictions are all based on laboratory test results as opposed to statistical calculations. igus offers a choice of 18 standard fibre reinforced materials in its products, all of them impregnated with solid lubricant throughout their wall thickness. So no matter how worn they become, the running properties remain the same. Latest developments include a rattle free ‘zero clearance iglidur’ bearing, in which the ends of the bearing element nip into the shaft and deflect a little as it rotates. Hollow carbon fibre shafts are available for low weight and high speed applications, and the company has also developed polymer trapezoidal leadscrew nuts with the load bearing capability of brass but without the need for lubrication. • Identified trends include a movement towards the supply of packaged solutions as opposed to the traditional approach of standard bearings bought from a catalogue • Rotary ball bearings made in the Far East are now down to 3mm OD with linear bearings down to 2mm rail widths